Strain Energy Decomposition Influence in the Phase Field Crack Modelling at the Microstructural Level of Heterogeneous Materials

Abstract

The prediction of a crack initiation and propagation occurring on the microstructural level of heterogeneous materials can be a very demanding problem. According to the results of recent investigations, the emerging phase field approach to fracture has a strong potential in modelling the complex crack behaviour in a simple manner. In this study, recently developed phase field staggered solution scheme with the residual norm stopping criterion has been employed for the fracture analysis of heterogeneous microstructure exhibiting complex crack phenomena. The microstructural geometries based on the metallographic images of the nodular cast iron and the material properties of an academic brittle material have been used in numerical simulations where the graphite nodules have been considered as porosities. Two commonly used energy decomposition models, the spectral decomposition and the spherical-deviatoric split, and their effects on the results of the phase field modelling are investigated. Numerical results show that the proposed algorithm recovers the complicated crack path driven by the complex microstructural topology.